I. Field of the Disclosure
The technology of the disclosure relates generally to sniffing and logging data on a bus for error detection.
II. Background
Computing devices use one or more buses to convey data between components within the computing device. In mobile computing devices such as smart phones, one such bus is the serial low power inter-chip media bus (SLIMbus). The SLIMbus was developed with the MIPI® Alliance and supports communication between baseband or application processors and peripheral components. The SLIMbus is particularly well suited for digital audio data streams, although other data may be conveyed over the bus.
The SLIMbus is implemented as a synchronous two-wire, configurable time division multiplexed (TDM) frame structure. The two wires carry the data line and the clock line so as to interconnect multiple components in a multi-drop bus topology. The data line has control and data information. One common use of the SLIMbus is to connect an applications processor to a codec that performs analog to digital or digital to analog conversion. During a design phase of a computing device that incorporates a SLIMbus, the designers may need to debug the communications between the applications processor and the peripheral. Even after the design phase, if a new peripheral is coupled to a SLIMbus within a computing device, there may be issues ensuring that such new devices are able to couple to the SLIMbus correctly which require additional debugging. The primary way to debug in this context is to “sniff” the data on the data line and capture or log the data so that it can be examined for possible sources of error.
Currently, the sniffing and logging is done using an external device that is supplied by an entity that does not make components that use the SLIMbus. One exemplary external SLIMbus sniffer is the SLIMbus Protocol Analyzer, sold by LnK sprl of Belgium (www.lnk-tools.com). Use of such an external device is cumbersome in that leads must be attached to the SLIMbus. Attaching such leads may be difficult in the confined space of the housing of the mobile terminal and/or may require that the bus be removed from the housing of the mobile terminal during testing. Furthermore, currently commercially available sniffing devices are expensive. The expense may mean that a design entity may only have a few such devices which must be shared between multiple design teams trying to perform testing. As yet another inconvenience to the parties doing the testing, the wires used to couple the external device to the SLIMbus have resistive-capacitive loads which may interfere with signal acquisition. As yet another issue with the external testing devices, as bus speeds increase, it is becoming increasingly difficult for the external testing device to capture and record all of the data on the SLIMbus. Thus, there needs to be a more effective system or technique with which to detect errors and record actions on a bus.